C++ can't call same function twice with different parameters - c++

Question

I have a C++ program that calls the same function tempGauge() twice. It hits the first call then skips the second call and goes to userData() and gives me the error "finished with exit code 6". when I comment out the first call the second call works as expected and ends with the exit code 0.
int tempGuage(int &array, int &actDay);
void userData();
int main() {
const int totalTemp(10);
int firstDay[totalTemp];
int secondDay[totalTemp];
int dayOne = 1;
int dayTwo = 2;
tempGauge(firstDay[totalTemp], dayOne);
tempGauge(secondDay[totalTemp], dayTwo);
userData();
return 0;
}
int tempGauge(int &array,int &actDay)
{
int i;
int maxTemps;
for(i=1;i < maxTemps;++i)
{
cout << "Enter # of temps on DAY " << actDay <<":";
cin >> maxTemps;
if(maxTemps <=0||maxTemps>=11)
{
cout << "Enter at least 1 but no more than 10. Try again.";
}
else
{
cout << "Enter the " << maxTemps << " temps(s):";
cin >>array;
i++;
}
}
return array;
}

Answer 1

Your code has undefined behavior.
Both of your calls to tempGuage() are passing in invalid int& references in the 1st parameter, as the [totalTemp] index is accessing an int that is beyond the bounds of each array. So, even if tempGauge() worked properly (which it doesn't), it would be filling in invalid memory. Since you clearly want to fill the arrays, you need to change [totalTemp] to [0] instead so you start filling at the beginning of each array rather than at the end.
Inside of tempGauge(), maxTemps is uninitialized when entering the loop, so the number of iteration is indeterminate. But, even if it weren't, the statement cin >>array; does not read in an entire array, like you are expecting. Even if it could, it would not know how many ints to read, since array is declared as a reference to a single int and you can't pass maxTemps to operator>>. You would need a loop to read each int individually, which you are trying to do, but you are not looping correctly. And also, cin >> array would need to be changed to cin >> array[i];, which won't work unless int &array is changed to either int (&array)[10] or int *array. In which case, main() would then have to be updated accordingly, by dropping the [0] when passing in each array.
With that said, try this instead:
#include <limits>
const int totalTemp = 10;
int tempGuage(int (&array)[totalTemp], int actDay);
void userData();
int main()
{
int firstDay[totalTemp] = {};
int secondDay[totalTemp] = {};
tempGuage(firstDay, 1);
tempGuage(secondDay, 2);
userData();
return 0;
}
int tempGuage(int (&array)[totalTemp], int actDay)
{
int maxTemps;
cout << "Enter # of temps on DAY " << actDay << ":";
do
{
if (!(cin >> maxTemps))
{
cout << "Invalid input. Try again.";
cin.clear();
cin.ignore(numeric_limits<streamsize>::max(), '\n');
}
else if ((maxTemps <= 0) || (maxTemps > totalTemp))
{
cout << "Enter at least 1 but no more than " << totalTemp << ". Try again.";
}
else
{
cout << "Enter the " << maxTemps << " temps(s):";
for(int i = 0; i < maxTemps; ++i)
{
while (!(cin >> array[i]))
{
cout << "Invalid input for temp " << i+1 << ". Try again.";
cin.clear();
cin.ignore(numeric_limits<streamsize>::max(), '\n');
}
}
break;
}
}
while (true);
return maxTemps;
}
void userData()
{
//...
}
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